U.S. Pat. No. 4,290,174 describes such a strip material which comprises a flexible polymeric bonding layer; a multiplicity of flexible, resilient, generally U-shaped monofilaments of polymeric material, each including a central bight portion embedded in the bonding layer in an array, two stem portions extending from the bight portion and projecting generally normal to an exposed major surface of the bonding layer; and enlarged, generally circular heads at the distal ends of the stem portions.
Fasteners can be made from two portions cut from the strip material described in U.S. Pat. No. 4,290,174 in which case the headed stems releasably engage each other, or from one portion used in combination with a different fastener portion such as one having a field of loops adapted to be engaged by the the headed stems.
U.S. Pat. No. 4,216,257 describes making such a strip material that includes a layer of low density resiliently elastic foam adhered to the surface of the bonding layer opposite its exposed major surface, and a layer of a soft tacky pressure-sensitive adhesive on the surface of the layer of foam opposite the bonding layer, which layers of foam and adhesive under many circumstances help in securely attaching the strip material to an object and help engagement of a portion of the strip material with another fastener portion.
U.S. Pat. No. 4,322,875 describes making fasteners from portions of two different strip materials having rectangular arrays of headed stems, each of which strip materials has stem portions that are about equally spaced in each direction to provide numbers of stem portions per unit length along the surface of its bonding layer in each direction that are different from and not a multiple of or evenly divisible by the number of stem portions per unit length on the other strip material in either direction to provide both a desired useful level of engagement and disengagement forces between the portions of the two strip materials and to restrict relative movement between the portions of the strip materials in directions parallel to their bonding layers when the fastener portions are engaged so that the rows of their headed stems are parallel.
While fastener portions cut from all of the strip materials described above have been found to be useful for some purposes, heretofore at least some of the materials from which these strip materials have been made has been mostly opaque and of a color that may not be the same as objects to which fastener portions from the strip materials may be attached, so that the fastener portions can detract from the appearance of some objects on which they are attached.